Sunday, August 25, 2019
Maritime Propulsion

June 20, 2019

Engine Overhaul for OSV Seven Atlantic

Subsea 7 Seven Atlantic (Photo: Royston)

One of the world's most advanced diving support vessels has undergone a comprehensive power plant refurbishment and maintenance program.

Engineers undertook the 30,000 running hour major service on the generator engines on board the 140-meter-long Subsea 7 Seven Atlantic, said power specialist Royston who completed the diesel engines overhaul.

The work by Royston saw the Wartsila W7L32 diesel generator No.5 disassembled to install new cylinder heads, air start valves, indicator cocks, injectors and cylinder seals. Relief valves, pistons and conrods, cylinder liners, bearing blocks, crankshaft and turbocharger were all sent to company’s Newcastle work shop for checking and essential repair work before being returned ahead of the final reassembly and inspection of the engine. Engineers also overhauled the turbocharger on the Wartsila W7L32 diesel generator No.3.

Requiring 12,000 running hour overhaul, the NA297 Napier turbochargers from both engines were removed, stripped, cleaned, inspected and balanced at Royston’s specialist test and repair facility, which features a Schenk H3BU horizontal balance machine alongside an IRD B5OU-290 instrument as part of a precision instrumentation capability to increase balance testing.

Following completion of the servicing work, incremental load testing in line with the engine manufacturer’s specification was also completed by engineers.

The 2009-built Seven Atlantic is one of the largest and most capable vessels of its type in the world. It operates a 24-person saturation diving system.

The vessel’s power plant package comprises six Wartsila 7L engines, each driving a 3360kVA Van Kaick generator, generating 6,6 kV (mains voltage). The propulsion installation runs on marine gasoil to provide power for propulsion, dive systems, crane activities and other consumers.